SKIN: Anatomy & functions

Skin is the largest organ system of body consisting of epidermis & under lying dermis & subcutaneous fat.

The epidermis is defined as keratirizing stratified squamous epithelium consisting of pilosebaceous follicles , nails , apocrine glands. It is a four layered structure [ basal , spinous , granular and corneal layer ]

The presence of following special cells viz. Keratinocytes, Melanocytes , Langerhans cells and Merkel cells helps the epidermis in maintaining its functions.



 

Dermis

Dermis is composed of fibrous connective tissue component , collagen & elastic fibers intermingled with grand substances. It gives support to epidermis & its appendages , blood vessels , nerves and cellular structures like mast cells , fibroblasts and Macrophages. And the arrector pili muscle system.


Functions of skin
The properties and functions of skin are:
Maintenance of integrity of the body
Protection from external injurious stimuli like Chemical,Hot /Cold stimuli,X- rays
  radiations etc.
As an excretory organ by sweating
Regulation of temperature
Absorption of UV rays – metabolism of Vitamin D
Acts as an sensory organ
Works as an immunological organ & barrier to various bacterial , viral , fungal
  infections.